Process for concentrating calcium ores



United States Patent PROCESS FOR CONCENTRATING CALCIUM ORES Merle N. Shaw, Canon City, C010.

No Drawing. Application January 18, 1955 Serial No. 482,674

2 Claims. (Cl. 209-166) This invention relates to a process for concentrating ores; and more particularly to a froth flotation process for concentrating ores containing a calcium compound as the essential constituent and associated with gangue.

An object of the present invention is to provide a process for concentrating ores in which a novel flotation agent is employed.

Another object of the present invention is to provide a process for concentrating ores in which the resultant concentrate contains the metal compound in substantially salable condition.

A further object of the present invention is to provide a process for concentrating ores which is simple in execution, positive in action, and commercially feasible.

Briefly stated, the process of the present invention comprises subjecting the ore to froth flotation separation in the presence of a flotation agent. The ore may be either the naturally occurring ore in finely divided form or the residue derived after suitable separation treatment. The ore may be any ore containing a calcium compound as the essential consituent and associated with gangue, for example, tactite, scheelite (CaWO powellite fluorspar (CaF The flotation agent may contain a substance selected from the group consisting of hydroxyethyl cellulose or carboxymethyl cellulose or in admixture with a medium petroleum refined fraction selected from the group consisting of refined or white mineral oil or refined mineral oil emulsified with an amine, either primary, secondary, or tertiary amine.

The following examples illustrate the types of ores and residues which may be concentrated or beneficiated by the process of this invention:

Example 1 The material used in this example was the residue obtained from a tungsten ore treating plant.

This material was made into about a 20% solid slurry. To this slurry was added suflicient sodium carbonate to produce a pH of about 9.8 to 10.0. 2.0 pounds per ton of white neutral mineral oil, 2.5 pounds per ton of sodium silicate, 0.16 pound per ton of hydroxyethyl cellulose were then added. These additions were followed by a nine minute agitation period. At the end of nine minutes two pounds of ammonia saponified Aliphat No. 44 E per ton of ore was added and agitated for an additional one minute. The pulp was then subjected to froth flotation for two minutes during which time a rougher tungsten bearing froth was removed. The froth thus removed was made into 5% slurry to which 2.5 pounds of sodium silicate and .048 pound of hydroxyethyl cellulose were added. The slurry was then subjected to froth flotation for one minute and a cleaned tungsten bearing froth removed. The tailing from the cleaner froth flota- 2,824,643 Patented Feb. 25, 1958 2 tion was returned to the head of the rougher froth flotation. Results are as follows:

Product Percent Percent Percent weight W a Recovery Example 2 The treatment of Example 1 was repeated, but with carboxymethyl cellulose used in place of hydroxyethyl cellulose, and the result was substantially the same as that obtained by the process of Example 1.

Example 3 The material used in this example was a high lime, tactite ore which had proven refractory to previous attempts to provide an economical procedure for its dressmg.

The ore was ground in a ball mill to a mesh grind with 5.3 pounds of sodium carbonate per ton of ore which was suflicient to give a pH of 9.9 in the pulp. 4.0 pounds per ton of ore of sodium silicate, 0.11 pound per ton of ore of hydroxyethyl cellulose .53 pound of white neutral mineral oil were added and the slurry agitated for one minute. After one minute agitation 0.5 pound of ammonia saponified aliphat No. 44 E was added and the pulp was subjected to froth flotation for one minute. After one minute of flotation 0.8 pound per ton of ammonia saponified aliphat No. 44 E was added and the pulp was subjected to froth flotation for two minutes, making a total time of three minutes during which the pulp was subjected to rougher froth flotation. The rougher concentrate was slurried, and 0.08 pound per ton of ore of sodium silicate was added. The slurry was subjected to first cleaner froth flotation for one minute. The first cleaner froth was slurried 0.05 pound per ton of hydroxyethyl cellulose and 0.08 pound per ton of sodium silicate were added and the slurry was subjected to a second cleaner froth flotation for one minute. The first and second cleaner tails were returned to the head of the rougher froth flotation. The second cleaner flotation froth was then subjected to treatment with a 2 parts of Example 4 The material for this sample was an ore containing sulfides, lime, partially decomposed lime, tactite and partially oxidized sulfides. This material was refractory to procedures available to the industry, producing a low grade concentrate and low recovery. The material was comminuted to about sixty five mesh and subjected to froth flotation for removal of the sulfides, using a xanthate and frother. Two pounds per ton of sodium carbonate, 1.5 pounds per ton of sodium silicate and 0.1 pound per ton of quebracho were added to the pulp and the slurry was agitated for 15 minutes. 0.5 pound per ton of ore of sodium carbonate saponified fatty acid, 0.65 pound per ton of white neutral mineral oil and 0.15 pound of hydroxyethyl cellulose were added and the agitation continued an additional 10 minutes. The pulp was then subjected to rougher froth flotation for three minutes. 0.25 pound of sodium carbonate saponified fatty acid was added and the pulp agitated for three minutes. The pulp was then subjected to middling froth flotation for eight minutes. The rougher flotation froth was slurried and subjected to a cleaner froth flotation for one minute. The middling and cleaner tails were returned to the head of the rougher flotation. The following results were obtained:

Product Percen t Percent Percent weight W Recovery Head 100.0 (1. 23 100. 0

Sulfide Concentrate rm 0. 85 0.10 0. 6

Tungsten Concentrate.-. 0.89 22. 92 91. 7

Telling 98.26 0. 016 7.7

Example The treatment of Example 4 was repeated, but with carboxymethyl cellulose used in place of hydroxyethyl cellulose, and the result was closely similar to that of Example 4.

Having thus described the invention what is new and desired to be secured by Letters Patent is:

1. The process for concentrating ores containing a calcium compound as the essential constituent and associated with gangue which comprises subjecting the ore to froth flotation separation in the presence of a flotation agent containing a substance selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose and a non-aqueous liquid.

2. The process for concentrating ores containing a calcium compound as the essential constituent and associated with gangue which comprises subjecting the ore to froth flotation separation in the presence of a flotation agent containing a substance selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose and a medium petroleum refined fraction selected from the group consisting of refined mineral oil, refined mineral oil emulsified with an amine.

References Cited in the file of this patent UNITED STATES PATENTS 2,222,728 Tartaron Nov. 26, 1946 2,569,672 Jackson Oct. 2, 1951 

1. THE PROCESS FOR CONCENTRATING ORES CONTRAINING A CALCIUM COMPOUND AS THE ESSENTIAL CONSTITUENT AND ASSOCIATED WITH GANGUE WHICH COMPRISES SUBJECTING THE ORE TO FROTH FLOTATION SEPARATION IN THE PRESENCE OF A FLOATION AGENT CONTAINING A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF HYDROXYETHYL CELLULOSE, CARBOXYMETHYL CELLULOSE AND A NON-AQUEOUS LIQUID. 